1. Field of the Invention
The present invention generally relates to a key cutting apparatus and, more particularly, relates to an apparatus for cutting keys according to key-lock manufacturers' codes.
2. Description of Related Art
Key-lock manufacturers conventionally space a series of notches along a key edge at incremental intervals and vary the depth of each notch by increments. For example, one manufacturer may use 0.156 inch intervals between each notch and vary the depth of each notch by increments of 0.015 inch. Another manufacturer may use 0.170 inch intervals between each notch and vary the depth of each notch by increments of 0.0125 inch. Consequently, a key produced by the first manufacturer will not open a lock produced by the second manufacturer. On the other hand, a significant number of key-lock manufacturers use the identical incrementation for spacing and/or depth.
Despite the use of identical spacing and depth incrementation, keys produced by different manufacturers are still distinct from one another. The reason for this is that key-lock manufacturers have adopted different first notch locations, measured from a shoulder or stop on the key, to commence their series of incrementally spaced notches. Likewise, key-lock manufacturers have selected distinct depth positions, measured from a rear or non-working edge of the key, as a datum or zero-position from which the depth of their notches are measured. As a result, although two key-lock manufacturers may use the identical incrementation for both spacing and depth, the selection of different initialization points will produce different keys.
In addition, not only do the spacing and depth of the notches cut into keys vary among manufacturers, the shape of the notches varies as well. Keys commonly have v-shaped notches. The width of the v-shape, and thus the incline angle (i.e., the angle formed between a line parallel to the key edge and the side of the notch) of its sides, however, vary from manufacture to manufacture.
Prior code key cutting machines have difficulty adjusting for the variations in the aforementioned parameters between key-lock manufacturers. Most code key cutting machines utilize a combined depth and spacing index system for each manufacturer. As over one hundred and fifty key-lock manufacturers exist in the United States alone, the difficulty of maintaining and organizing the necessary keys every manufacturer, will be appreciated.
U.S. Pat. No. 4,090,303 issued to Uyeda, however, discloses a code key cutting machine having an indexing drum with a plurality of rows of notches. Each row of notches corresponds to a spacing code of one manufacturer. The code key cutting machine additionally includes a separate depth measurement gauge for use with a graph card having a series of rows, each row having a series of incremental markings corresponding to a depth code of one manufacturer. Uyeda discloses using a single drum and card for several manufacturers. Nonetheless, a locksmith using the Uyeda machine must constantly change indexing drums and cutting blades when cutting keys for locks produced by different manufacturers. This procedure is cumbersome and time-consuming and increases the possibility of dropping and breaking the cutting blades and indexing drums due to the frequency of handling these components. In addition, the initial notch cut cannot be independently set from the spacing drum, and thus all key types which share the same spacing increments cannot be accommodated with a single drum.
Thus, these is a need for a code cutting machine readily adaptable to cut key according to the gamut of key-lock manufacturers' codes.